Studying the molecular mechanisms of tef (Eragrostis tef) antioxidant properties in human THP-1 monocytes

Brown tef (Eragrostis tef) grain extracts increase cellular glutathione (GSH) in THP-1 monocytes, however, the molecular mechanisms remained unclear. In this study, we found that the tef extracts induced luciferase activity by 19-fold in HEK293 cells stably expressing the luciferase gene under the control of the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element, indicating the activation of the antioxidant pathway. RNA-seq analysis revealed that the tef extract enhanced the expression of 87 genes, including some regulated by the Nrf2 transcription factor. Differentially expressed genes included ferritin heavy chain pseudogenes, tumor necrosis factor (TNF)-α, and solute carrier genes. Using LC-MS, we identified compounds that were differentially enriched in the active tef fraction as compared to the inactive fraction, including vernolic and α-linolenic acid, which were enhanced by over 60-fold. In summary, our findings indicate that tef grains contain phytochemicals that enhance the antioxidant levels through the Nrf2-signaling pathway.